org.omnaest.utils.cache
Class ConcurrentWeakReferenceCache<K,V>

java.lang.Object
  org.omnaest.utils.cache.ConcurrentWeakReferenceCache<K,V>

Type Parameters:

K -

V -

All Implemented Interfaces:

Serializable, Map<K,V>, Cache<K,V>

public class ConcurrentWeakReferenceCache<K,V>
extends Object

A ConcurrentWeakReferenceCache holds a given number of separated SynchronizedWeakReferenceCache instances, called segments.
Based on the number of segments the retrieval operation will block less long for a multithreaded call to get(Object), containsKey(Object), containsValue(Object), size() and isEmpty(), but any additional segment will increase the blocking time for any put(Object, Object), putAll(Map), remove(Object) and clear() call, as well as it is increasing the memory footprint since every segment will hold all the information within the Cache.

Author:

Omnaest

See Also:

Cache, Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface java.util.Map

Map.Entry<K,V>

Constructor Summary

ConcurrentWeakReferenceCache()
This does create a ConcurrentWeakReferenceCache which uses as many segments as the Runtime.availableProcessors() returns

ConcurrentWeakReferenceCache(int numberOfSegments)

Method Summary

void	clear()
boolean	containsKey(Object key)
boolean	containsValue(Object value)
Set<Map.Entry<K,V>>	entrySet() Returns an unmodifiable Set of all Map.Entrys within the Cache which only represents a snapshot in moment
boolean	equals(Object o)
V	get(Object key)
V	getOrCreate(K key, Factory<V> factory) Gets a cached value or creates a new one using the given Factory and puts the new value into the cache.
int	hashCode()
boolean	isEmpty()
Set<K>	keySet() Returns an unmodifiable Set of all keys within the Cache which only represents a snapshot in moment
V	put(K key, V value)
void	putAll(Map<? extends K,? extends V> m)
V	remove(Object key)
int	size()
Collection<V>	values() Returns an unmodifiable Collection of all values within the Cache which only represents a snapshot in moment

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ConcurrentWeakReferenceCache

public ConcurrentWeakReferenceCache()

This does create a ConcurrentWeakReferenceCache which uses as many segments as the Runtime.availableProcessors() returns

See Also:

ConcurrentWeakReferenceCache

ConcurrentWeakReferenceCache

public ConcurrentWeakReferenceCache(int numberOfSegments)

Parameters:

numberOfSegments -

See Also:

ConcurrentWeakReferenceCache

Method Detail

size

public int size()

isEmpty

public boolean isEmpty()

containsKey

public boolean containsKey(Object key)

containsValue

public boolean containsValue(Object value)

get

public V get(Object key)

put

public V put(K key,
             V value)

remove

public V remove(Object key)

putAll

public void putAll(Map<? extends K,? extends V> m)

clear

public void clear()

keySet

public Set<K> keySet()

Description copied from interface: Cache

Returns an unmodifiable Set of all keys within the Cache which only represents a snapshot in moment

values

public Collection<V> values()

Description copied from interface: Cache

Returns an unmodifiable Collection of all values within the Cache which only represents a snapshot in moment

entrySet

public Set<Map.Entry<K,V>> entrySet()

Description copied from interface: Cache

Returns an unmodifiable Set of all Map.Entrys within the Cache which only represents a snapshot in moment

equals

public boolean equals(Object o)

Specified by:

equals in interface Map<K,V>

Overrides:

equals in class Object

hashCode

public int hashCode()

Specified by:

hashCode in interface Map<K,V>

Overrides:

hashCode in class Object

getOrCreate

public V getOrCreate(K key,
                     Factory<V> factory)

Description copied from interface: Cache

Gets a cached value or creates a new one using the given Factory and puts the new value into the cache.

Specified by:

getOrCreate in interface Cache<K,V>

Returns: